is there no free update for the z3ta+2 for reg. user in the X1C update?

I certainly wouldn't think so.  the z3ta+2 just came out.  if there's an update needed I'm sure it's not finished yet.

also, everyone who has X1 doesn't have z3ta+2 - so there's no reason they would bundle an update to z3ta with X1's updates.

No, I called the Cakewalk store and asked for clarification before I upgraded to X1. X1 comes with Z3TA 1.5, if you want Z3TA 2 you have to pay for it separately. I saw that if you bought Z3TA 1.5 standalone after July 18 (but before Z3TA 2, obviously) you got a free upgrade to V2, but that did not apply to Sonar.